The present invention is directed to an automated warehouse system having at least two stacked longitudinally extending racks that are laterally separated by an aisle and automated carriages at some or all of the levels to store articles to and retrieve articles from each of the racks at that level, and a method of storing articles to and retrieving articles from such automated warehouse system.
In such an automated warehouse system, the articles are supplied to each level of the warehouse system with a lift arrangement. The carriages retrieve articles from storage positions in the racks and dispatch the articles to the lift arrangement or retrieve articles from the lift arrangement and store the articles to a storage position on one of the racks. A computer system coordinates the lift arrangement and the carriages in order to be able to retrieve any articles stored to the automated warehouse system when that article is needed, for example, to fulfil an order in an e-commerce or mail-order system. The article may be a container, such as a tote, that contains a plurality of individual items of the same type, or stock-keeping unit (SKU), or a mixture of different types of items, or SKUs. Alternatively, the article may be a self-contained item that is packed by itself. The number of articles that can be stored to and retrieved from the automated warehouse system in a given period of time is a measure of the efficiency, or through-put, of the system.